“This route climbs through old farming fields and over hills. Cerro viejo subiendo por potrerillos.
— Emilio Garcin
This is a great trail, and will get your heart pumping. Starting in the town of Potrerillos, you go up right off the start. The first part is a bit rocky and you go up some switchbacks up until you reach the ridge line of the mountain. Then, the vegetation starts to change, the trail seems to have fewer rocks and lots and lots of trees!
This goes on until you reach the summit, which has some phone antennas and a small house for the people in charge. The view is amazing.
Then, you have to go back the same way you came, which is downhill all the way back to Potrerillos.